MultiPath TCP – Linux Kernel Contributions

With the way the Internet is being used today, from carrying Voice to TV there is a high demand for reliability from the Internet. However it’s proving more and more difficult to predict failures in the network, to spot flash crowds or to predict when the next distrubited denial of service (DDoS) attack will happen.

The Internet has being trying for years to route around these network failures, however to date once the routing protocols have done their job, only a single path, or small number of equal-cost paths are used to transmit packets, ignoring possible alternative paths.

MultiPath TCP is a new way of making the different network downlinks available to the transport protocol, and allowing for the establishment of more than one path between the same pair of servers for the same connection. In effect with MultiPath TCP we can make use of the additional paths that are ignored by the Internet routing system. Doing so can provide more bandwidth and better resiliency for the user and higher network utilisation for network operators.

As of March 2013 the first stable implementation of MultiPath TCP was released for the Linux Kernel and there a contribution in there from our very own John Ronan, a researcher in the Security research unit of the TSSG.

As John points out, “multi-path transport protocols will be the key to making the Internet more robust and more responsive to congestion”.

This first open source software release will bring Multi-Path TCP a step closer to the path of being a fully blown standard from the IETF.